1. Technical Field
The present invention relates generally to devices for obtaining a blood sample and more particularly to devices for puncturing an individual's finger, ear lobe or heel for diagnostic purposes.
2. Background Art
The processing of blood assays for diagnostic purposes has largely been carried out within centralized diagnostic clinical laboratories. Blood tests typically require samples taken from a vein draw of whole blood. In recent years, new systems have emerged for alternate site markets. Increasingly, testing is performed within a doctor's office, mobile units, geriatric care homes, drug stores, and even the patient's home. Home monitoring of blood glucose levels for diabetics is one example of self-testing. Each such self test requires a droplet or two of fresh finger-puncture whole blood.
Consumable finger lance devices for puncturing the skin of a patient are known. Lance needles are typically installed into pen-like devices which are spring loaded and push-button actuated. Such devices can be easily reused despite warnings against reuse. A first use may contaminate the lance of the device, whereafter the second use may cause the contamination to enter the system of the patient. Within mobile units for testing of such things as cholesterol, an accidental or purposeful reuse can result in cross-contamination of patients.
Another risk involved in drawing blood from a patient is accidental puncturing of hospital personnel in the removal or disposal of lance needles from puncturing devices. Serious health hazards result from such accidental post-use puncturing.
A less dangerous concern involves apprehension of the user who anticipates that pain will occur upon actuation of a release button. U.S. Pat. Nos. 4,416,279 to Lindner et al. and 4,580,564 to Andersen teach devices to lessen the apprehension of the user. The Lindner et al. patent uses an actuating method in which there is no clear indication when a plunger will be triggered so that apprehension is reduced. Anderson uses a weight to force the lance into a user, teaching that elimination of a trigger reduces trauma.
An object of the present invention is to provide a puncture device which is restricted to a single use and which completely encloses a lance to prevent accidental secondary puncturing. Another object is to provide such a device which is inexpensively manufactured and which reduces patient trauma and discomfort.